Having a thermometer installed in your brew pot allows you to track wort temperature accurately at all times. The Blichmann BrewMometer is one of the best on the market as it features a 3" dial face that is hermetically sealed, large lettering and a fine pointer so you're not guessing the temperature, and suggested mash temps are already printed on! The NPT version comes with a male 1/2" NPT pipe thread that allows for quick and easy installation on a pot that has a corresponding female NPT port.